"I'm not one to usually use the language, but it's pure hell knowing that unless something comes about, that he could by laying there, you know, and put to death for something that didn't happen," said his Havard's mother, Cheryl Havard Harrell.

In 2002, an Adams County jury convicted Havard in connection with the death of 6-month-old Chloe Britt. At the time, Dr. Steven Hayne was the only state pathologist in Mississippi.

"They just wanted a conviction and I feel like they used Dr. Hayne to get their conviction," Harrell said.

Former state Supreme Court Justice Oliver Diaz said Hayne's testimony that Havard shook the baby to death went unchallenged because the public defender couldn't afford a second exam.

"He was denied the use of his own expert in that case, but they allowed the state to proffer Dr. Hayne as an expert for the state," said Diaz, who served on the Mississippi Supreme Court from 2000 to 2008.

Diaz was one of two justices who voted to throw out Havard's conviction in a 2006 appeal. But in the end, the majority of the high court upheld the death sentence.

"I think there probably are people in prison who have not committed the crime they're convicted of committing," Diaz said.

Now, a decade later, Hayne is the subject of a huge legal fight. Hayne claims he performed about 1,700 autopsies a year between 1987 and 2008. But if he worked seven days a week, with no vacations and no weekends off, that would mean he did 4.5 autopsies every single day for 21 years. The National Association of Medical Examiners forbids anyone from performing more than 325 autopsies in a year.

Levon Brooks and Kennedy Brewer both spent more than 15 years in prison because of testimony by Hayne. The two men were convicted in Noxubee County in two separate murder cases.

Brooks was convicted in the 1990 rape and murder of his ex-girlfriend's 3-year-old daughter.

Brewer was convicted in 1995 in connection with the death of his girlfriend's 3-year-old daughter, who was also raped and killed.

In both Brooks' and Brewer's trials, Hayne and forensic dentist Michael West testified that they found men's teeth marks on the victims. But later, the Innocence Project uncovered DNA evidence that proved Hayne and West were wrong.

A judge exonerated both men in 2008.

"I hope they don't lock no innocent people up no more," Brewer said in 2008.

After that case, the state removed Hayne from his post as state pathologist. Now lawyers from the Innocence Project say hundreds of convictions could be in jeopardy.

For weeks, 16 WAPT's Meg Pace has tried to speak with Hayne about the thousands of cases that could be thrown out. At his home, he declined an interview.

A 16 WAPT crew was able to catch up with Hayne on Friday. He said he worked seven days a week as the state's pathologist.

"I don't see that I did anything incorrect," Hayne said. "The proof of the pudding is in the quality of the work."

Meanwhile, the state has revamped how it handles investigations.

"Now the crime lab is fully staffed," said Mississippi Department of Public Safety spokesman Warren Strain.

Strain said the state crime lab has a very large case load, but all the work is split between three pathologists.

"Between the three physicians, it's spread out pretty evenly and certainly within the standards," Strain said.

Diaz said the state has made progress over the past few years.

"We have taken steps, but we haven't done enough and one of the main things we need to do is review in cases in which Dr. Hayne had testified in trial," Diaz said.

Family members said Havard's time is running out. The 34-year-old has already spent 10 years on death row.

The Obama administration will unveil a major climate change plan Monday aimed at a large reduction in greenhouse gas emissions from the nation's coal-burning power plants, a senior administration official told CNN.